Circuit breaker



11, 1927 4 Sheets-Sheet 1 Dec. 30, 1930. F. a. VON HOORN CIRCUIT BREAKER Original Filed Aug.

YINVENTOR, Fed G van hoorn AT'IEORNEY Dec. 30, 1930. F. s. VON HOORN cmdumanmxmz 4 Sheets-Sheet 5 Original Filed Aug. 11', 1927 [III III] III ATTORNEY Dec. 30, 1930.

F. G. VON HOORN CIRCUIT BREAKER Original Filed Aug. 11, 1927- 4- Sheets-Sheet 4 I I '47 II II [I INVENTOR Fred 6 van ho'orn ATi'ORNEY Patented Dec. 30, 1930 UNITED STATES,

FRED G. VON HOORN, OF BRIDGEPOB'I, CONNECTICUT, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA cmcurr Bananas.

Application filed August -11, 1927, Serial No. 212,289. Renewed July 16, 1930.

My invention relates to circuit breakers and particularly to circuit breakers for con- '-from sheet metal which are inexpensive to trolling lighting and small-motor circuits.

An object of my invention is to provide a circuit breaker that shall be adapted for use in distributing panels to take the place of the I usual switch and fuses or which may be used facture.

to control domestic-appliance motors and the like.

A further object of my invention is to provide a circuit breaker that shall be trip free from the operating handle and which shall be compact and relatively inexpensive to manu- A further object of my invention is to provide a circuit breaker wherein the switch contact is retained in closed position by a toggle in order to secure maximum contact pressure-and to reduce the heating-of the switch contact.

A further object of my invention is to provide 'a circuit breaker having the abovenoted characteristics, wherein the toggle is supported by a carrier controlled by a current-responsive element, and wherein the switch contacts are caused to be separated by overload or short-circuit conditions.

These and other objects that will be made apparent throughout the further description of. my invention are attained by means of the circuit breaker hereinafter described and illustrated in the accompanying drawings,

wherein, a

Figure-1 1s a sectional view of the circuit breaker showing, in plan; view, the circuitbreaker apparatus,

- Fig. 2 is a vertical section through a circuit breaker,'showing parts thereof in side elevation, thecircuit-breaker parts being in the closed position.

Fig. 3 is a view, similar to that of Fig. 2, with the parts shown in an intermediate operating position, and v Fi 4 is a view,'sim1lar to that of Fig.2,

showing the parts of the circuit breaker in the 0 en position.

Re erring to the drawings, the circuit breaker includes an insulating base 5 that is provided with a pressed-metal cover 6 for enmounted upon the base 5. The circuit -break er comprises, principally, parts stamped element 17 of U-shape. The other leg of the bimetal element is supported upon a terminal 18.

The insulating base is provided with a pair of terminals 19 and 21 having terminal screws 22 and 22' thereon for receiving the line conductors. The terminal 18 is connected to the terminal 19 by a strap 23. disposed on the under side of the insulating base 5. Current enters the circuit breaker through the terminal 19, stra 23 and terminal 18, and passes through the imetal thermal element 17, switch arm 11, switch contact 9, stationary contact plate 8 and terminal 7 that is connected to the terminal 21 by a strap 24. The feed conductor, may however, be connected to the terminal21. a

The circuit-breaker operatin mechanism is mounted upon a supporting racket 25 of U-shape that is attached to the insulating base 5 b means of bolts 26. A toggle carrier or crad e 27 is pivotally mounted upon the bracket 25 and rotates about the'pivot shaft 28-that is secured in the free ends of the sidei adapted to receive the free end of a toggle link 34 which is also of U-shape and comprises a pair of side plates 35 that are connected by an integral cross bar 36. Each side plate 35 of the toggle link 34 is forked, at

engage the apices of the notches 33 of the 3 carrier 27, the-apices of the notches serving as ivot points for the outer end of the toggle lin 34.

.. .The bimetal thermal element dle 47 that extendsthrough a slot.48 1n the I which the free end of the toggle .pivots;

' normally e sr "opera" hers are in v.hy moving the operating ward to the 'A toggle link 37 of U-shape is pivotally connected to the link 34 by means of a knee ivot'shaft 38, the ,side plates thereof being 'sposed on opposite sides of the link 34 and connected by an integral cross bar 51. The free ends of the side plates of the link 37 are pivotally connected to the switch arm 11 by means of the pivot shaft 39 that is secured to the side plates of the bracket 12 that is also of U-shape. v

The to gle carrier or cradle 27 isreleasably retained in the set osition shown in Figs. 2 and 4 by'means o the bimetal ther mal element 17 that is provided with a metal "latch 41 insulated from the bimetal element 17 is so designed that it will move downwardly when heated by an excess current, such as is-incident to an overload or short-circuit condition. When the latch 41 clears the shoulder y means of insulating washers 43 on the carrier or cradle 27, the cradle is free to rotatecounter-clockwise in response to the tension exerted thereon by an: overcenter spring 44 that -is pivoted, at one end, to the'knee pivot shaft 38 of the toggle and, at the other end, to an operating handle member 45 that is pivotally mounted u n a shaft 46 carried by the bracket 25. he handle member is provided with'an insulatin hancover 6,'the handle-being provided with extensions 49 within the-cover 6 forclosing the slot 48in all-positions of the operating handle. Fromthe foregoing, it-is ap arent that the carrier or cradle .27 1S norm y biased in a counter-clockwise direction by the spring 44.

l handle 47 is moved to the position .Fig. 2, which will cause the spring 44 to "ofthe spring 44 will cause] knee shaft or pivot 38 of the toggle will be moved downward and over-center, thus causing the toggle to collapse and permitting the spring 44 to move the contact arm-'11 to the open position shown in Fi 4.

' To close the circuit breaer, the 0 rating own in move the toggle links to the made 'tlon and thereby move the switch arm 11 into the closed position shown in Fig. 2. Q

Under short-circuit or overload conditions, the bimetalthermal element 17 will be withdrawn t'o-the position shown in Fig. 3 wherein it releases the carrier orcradle' 27. The

spring 44 immediately contractsand breaks the toggle and movesthe sw tcharm 11 to-- ward open position, the ultimate o n position of the switch contact 9 being in V 'cated in I dotted lines in Fig. 3. When the toggle links have moved to the osition shown in Fig. 3,

movement of the llIlk 37 is arrost'edby engagement of the cross bar 51 with the cross bar 32 of the cradle 27. Further contraction clockwise rotation of the operating member 45 and handle 47, such movement being permitted by reason of the arcuate slot'l52 provided in the side plates of the operating member 45. The pivot shaft 28-extends through the slots 52 and serves as aguide for the outer end of the operating member'45. v

A carriage or cradle-resettingspring 53 is i pivotally connected to gthe shaft 28 at one end and, at the other end, to an arm 54 onthe inner end of the operating member 45.

As illustrated in Fig. 3, when the operating arm and handle are in the closed positions shown in Figs. 2 and 3, the end of the spring attached to the arm 54 lies slightly be owa lineconnectn iglthe centers of the pivot shafts ios which, in the pesitionshown n 2, serves .46 and '28. e spring 53 is an over-center to. hold the toggle in the made orc osed posisprin and, therefore, serves to yieldingly re tain t e operating handle in the clos position, wherein the knee pivot shaft 38 is, slightly above a line connecting the pivot shaft .39 and the apex ofthe notch 33 about ,tion.. When the operating A lug 55. on the operating arm moves the position shown in ,F' 4, thus resetting the cradle in set position I e the switch'armf handle 47 are turned'in a member 45 and ockwise direction,

.by the spring 44, the end of the attached to the arm-54 of the operating memher 45 is moved above the center line connect- Y 1 ing the shafts 46- and 28 and immediately causes clockwise rotation of the operating member 45 and opera handle 47.

shoulder 56 on the carrier or cradle 27 v the cradle with the operating arm-to and remains in the open postion and'while thelop crating arm and handle occupg the open pomtion, as shown in Fig. 4, whic indicatesthat the circuit breaker has opened. When the,

operating arm is moved to the upper position,

the switch contacts will befmoved to closed Since the carrier or cradle 27 will be drawn a position in the manner previously described.

sembled and the number of operating parts is Cal scope of my invention, as set'fprth in the l the contact mem to the opened position shown in Fig. 3 regardless of the position of the operating handle 47, the circuit breaker may open under short circuit and overload conditions while the operator is holdin the operating handle 47. The circuit brea er is, therefore, trip free of the handle and cannot be retained in closed position under overload or short circuit conditions by the operator. If a shortcircuit condition prevails after the circuit has been interrupted and the operator attempts to reclose the circuit, the bimetal thermal element will instantly release the cradle when the contact 9 is nfigved into engagement with It will be noted that there is but one latch employed in the structure, that-being the latch 41 carried by the bimetal thermal element. The ma'or portion of the parts of the circuit brea er are stamped from sheet metal and are, therefore, inexpensive to manufacture. Theparts may be readily asredu'ced to a minimum.

The circuit breaker may be rendered tron ble indicating by eliminating the resetting sprin 53, in which event the operating handle W111 be moved to anintermediate position when the cradle 27 isreleased by the bimetal element. 7

While I have illustrated only one embodiment of my invention, it will be apparent to those skilled in the art that various changes, modifications, substitutions, additions and omissions may be made in the apparatus illus-' 'trated without departing from the spirit and P" pended claims.

I claim as my invention: 1. The combination witha switch contact supported in closed position by a releasable carrier controlled by a current-responsive element and movable relative to" the carrier to open and closed positions, of means for "automatically returning the carrier to set position after the latter has bee released by the said element.

7 2. The combination with a switch contact.

. supported in closed position by a releasable carrier and movable relative to the rrier to open andclosed positions, the sa d carrier being retained in set position by a currentresponsive element and causing opening movement of the switch contact when reof means for automatically return-' leased, ing the carrier to'set' position after the latter has been released by the said element.

3'. The combination with a switch contact supported in closed position by a releasable carrier p n e moving the switch contact to open and closed positions while the carrier-is in setposition,

that is retained in set position by a current-responsive element and which causes movement of the switch contact whenreleased, and an operating means; for

of means resettable by the operating means,

for automatically returning the carrier to set position after it has been released by the cur,-

rent-responsive element. I

5. A circuit breaker comprising a contact member movable to open'andclosed positions,

a carrier movable to set and released positions, acurrent-responslve means for releas- -ably retaining the carrier in set position, a toggle having'one end supported by the car rier and the other end connected to the contact member for releasably retaining the contact member in closed position when the carrier is in set position, an operating member,

an over-center spring connecting the toggle and operating member, for making and breaking the toggle for causing closing and opening movements; respectively, of the contact member, and an over-center spring for actuating the operating member and automatically returning the carrier to set position afterthe current-responsive means has released i a 6. A circuit breaker comprising a contact mem bcr movable to open and closed positions, a. carrier movable to set and released os'itions, a current-responsive means for reeasably retaining the carrier in set position, a toggle. having one end supported by the carrier and the other end connected to the contact member for'releasably retaining the contact member in closed position when the carrier is in set position, an operating. member, an over-center spring connectin the toggle and operating member, for ma mg-Yand reaking the toggle for causingclosing and opening "movements, respectively, 0

the

contact member, and means for, automatical- 1y returning the carrier toset position after it has been released by the currentresponsive element.

37 7. A circuit breaker comprisin a contact.

member-movable to open and c osed posi tions, a pivotally mounted carrier movable to set 'andfi'eleas'ed positions, a current-respon- S 1'V8 meansfor releasably retaining the car.- rier m set. position, a tog le having one end pivotally connected to t e carrier and" the other end pivotally connected to the-contact member for.- releasablyretaining the. con: tact member inclosed position when the toggle 1 s 1n the made position, a. pivotally mounted operatmghehandle,pan over-center knee'of the toggleand the operating handle, for making and breaking the toggle pivot causing closing and opening'movements, respectively, of the contact member, an over-center spring for releasably retaining the operating handle'in either open or closed ltion, and for automatically returning t e carrier to set position after the latter has been released by the current-responsive means- 8. The combination with a switch contact supported in closed position by a releasable carrie'r controlled by a control element and movable relative to the carrier to open and closed positions, of means for automatlcally returning the carrier to set position after the latter has been released by the said element.

9. The combination with a switch contact supported in closed position by a releasable carrier that is retained in set position by a control element and which causes opening movement of the switch contact when released, thefsaid switch being movable-relative to the carrier to open and closed positions, of means for automatically returning thecarrier to set position after the latterhas been released by the said element.

In testimony whereof, I have hereunto I zigggcribed my name this 6th day of July, FRED G. VON HOORN. 

